In his biography of the late Apple co-founder, author Walter Isaacson said Jobs saw textbooks as another market ripe for disruption by releasing digital versions on the iPad.

Digital textbooks usually include dynamic elements, like pictures or video clips. Chaim Gingold has taken that to the next level with "Earth Primer", an app that teaches you about our planet by letting you play with an interactive model of it.

"Earth Primer" allows you to summon rainclouds to send streams of water cutting through mountains to demonstrate how erosion works instead of just telling you. You can also raise the sea level, create glaciers, even move continental plates around - all to explain the inner workings of the Earth.

Rick Carrier was barely out of his teen years when he helped save tens of thousands of lives. If there is anyone fit to be called a hero, it's him – and a very unassuming one at that.

Carrier was the first American to stumble across the Nazi-run Buchenwald concentration camp in Germany on April 10, 1945. It was his twentieth birthday. The next day he returned with reinforcements, and helped liberate Buchenwald.

At 90 years old, the World War II veteran's recollection of the sights, smells and emotions at the very moment he helped liberate the camp are just incredible.

The Legend of Zelda: Ocarina of Time is one of my favorite games ever. I feel like I should know everything about the game, since I've finished the roughly 20-hour main storyline several times over the last 16 years.

But he’ll tell you, working to save endangered animals is especially meaningful to him.

“I feel they have a personality – just like us,” Yao said of the rhinos and elephants he met during a trip to Africa two years ago. “Some are very funny. Some are very shy. They have a good memory too – and know the people who treat them very well.”

The situation in Ferguson, Missouri is a reminder of the deep racial division in America.

Protesters in Ferguson and across the United States feel that Michael Brown was singled out by police because of his race.

CNN contributor L.Z. Granderson says there is a lack of trust between minorities and police, as well as a lack of empathy between blacks and whites in the country.

It's a problem he's experienced way too often.

"I've lost count the number of times I've been pulled over by a police officer," he tells me from Ferguson. "The first time that an officer pulled a gun out on me, I was 12 years old. He told me I looked like someone."

"We're talking about a 30 year gap in my life in which I continue to look like someone that police are interested in," Granderson says. "I have never committed a crime. I have never been prosecuted. But I keep feeling I am being persecuted."

Here's Granderson on the racial divide in America and the anger surrounding the Ferguson grand jury decision.